NEW YORK CITY — The persistent peridevice leaks in percutaneous left atrial appendage (LAA) closure may be addressed by applying pulsed field ablation (PFA) during the procedure, the STUN-AF study suggested.
In this observational cohort study of 327 people undergoing concomitant PFA for atrial fibrillation (Afib) and LAA closure at three U.S. centers, it was apparent that those who got PFA on the LAA were more likely to have no peridevice leaks on imaging at both 4 months (71% vs 36%, P<0.001) and 12 months (96% vs 58%, P<0.001).
Ablation of the LAA, a technique to eliminate residual contractility just before LAA occlusion, thus reduced peridevice leaks and was backed by a correlation in lower LAA emptying velocities, as well as favorable safety data, reported Vivek Reddy, MD, of Mount Sinai Fuster Heart Hospital in New York City.
“The physiological conclusion is that residual contractility is a modifiable contributor to an incomplete appendage seal,” Reddy said at the New York Valves annual meeting hosted by the Cardiovascular Research Foundation. “Consider this in patients undergoing concomitant ablation.”
“We would certainly want to see a future prospective trial, and I think this has implications for future appendage device iterations,” he added.
Peridevice leaks are a known problem associated with increased ischemic strokes and other thrombotic events after LAA occlusion, a procedure itself indicated to prevent strokes in the first place among Afib patients with a bleeding risk too high for long-term anticoagulation therapy.
Reddy noted that strategies to reduce peridevice leaks have focused on improved device design, namely better conformity to LAA ostial anatomy, optimizing device sizing, and refining implantation technique with deflectable sheaths.
Nonetheless, the incidence of these leaks has not appreciably declined, he said. “So we asked the question, well, why do peridevice leaks occur? Well, of course, some of it probably is related to device appendage mismatch, and round device and oval anatomy, but perhaps there’s another problem, which is the mechanical contraction of the appendage causing this to-and-fro flow around the device, which inhibits the device to seal properly.”
Session discussant Puvi Seshiah, MD, of the Christ Hospital in Cincinnati, agreed that there is an issue of residual contractility.
“Contractions of the left atrial appendage do matter when you have a device, and you see this sometimes in a very contractile left atrial appendage, the Watchman does not sit right. And so ablating this [LAA], you stop the motion, and hence you’re able to seat the device well. It tends to anchor better,” he said.
“This is going to become important because we are starting to recommend left atrial appendage occlusion as an [alternative] option to medical therapy, so this is a first step in the direction of trying to address and improve peridevice closure,” according to Seshiah. “It’s sort of sobering that only about 50% of left atrial appendage devices actually have complete closure now.”
Reddy suggested that future LAA closure devices be designed to also allow the operator to deliver some ablating energy into the LAA — acknowledging that the expectation should be some “stunning,” as durable isolation of the appendage is hard to achieve.
The STUN-AF cohort had a mean age of 76 and was 58% men. Paroxysmal Afib was noted in 55%, and the CHA2DS2-VASc score was on average 4.3. The most common indications for LAA closure were bleeding (41%) and falls (32%).
The PFA catheters used were mostly a mix of Farawave and Sphere-9, with few patients undergoing PulseSelect and Varipulse PFA.
The study cohort was split between those who got PFA for Afib then either got LAA closure alone, or those who also got additional PFA on the LAA. Patients who made it to 12-month TEE or CT imaging were 83 who got LAA ablation and 43 who did not.
“Ultimately, we do need a randomized trial,” Reddy stressed. “Follow-up imaging modality did differ between participants. We didn’t have 12-month imaging in all patients … and of course we had insufficient patients to comment if this results in any change in clinical outcomes.”
As for safety, periprocedural adverse events with LAA ablation were rare, mainly limited to a few cases of transient ischemic attack (0.5%) and bleeding (1.4%).
During 3-month follow-up of the intervention group, there were few deaths (0.9%), heart failure hospitalizations (0.9%), stroke (0.5%), myocardial infarction or coronary revascularization (1.8%), or major bleeds (2.3%).
